{The first question should always be "How was it?", an open question to encourage the user to speak freely.}
“How was it?”
Let the user speak, and encourage them, until they dry up and stop of their own accord.
{Next, ask a series of standard questions prepared in advance for every test user. More general questions should come first, more specific questions later. At least four standard questions should be asked in this section. Two are already suggested, add at least two more of your own.}
At this point, ask any questions which arose during the test with each particular test user.